Production of nitrids.



UNITED STATES PATENT OFFICE.

CARL BOSCH AND ALWIN MITTASCH, OF LUDWIGSHAFEN-ON-THE-RHINE, GERMANY,

ASSIGNORS. TO BADISCHE ANILIN 8r SODA FABRIK, OF

RHINE, GERMANY, A CORPORATION.

LUDWIGSHAFEN-ON-T'HE- PRODUCTION OF NITRIDS.

No Drawing.

To all whom 'it may concern:

Be it known that we, CARL Boso1-1,'Pl1. D., and ALWIN MITTASCH, Ph. D., chemists, subjects, respectively, of the King of Prussia and the King of Saxony, residing at Ludwigshafen-on-the-Rhine, Germany, have invented new and useful Improvements in the Production of Nitrids, of which the following is a specification.

In the specification of British Letters Patent No. 7 507 A. D. 1909 is described the production of aluminium nitrid by heating a mixture of alumina or aluminous com-' pounds and carbon'in the presence of nitrogen at a temperature not exceeding 2,000 O," and it is stated that of course the addi tion of materials which hasten the reaction,

such as copper, iron, hydrochloric acid, sulfurous acid, or aluminium chlorid, enables the temperature at which the reaction occurs to be reduced. Further inthe specification of .British Letters Patent by heating silica and carbon in the presence of nltrogen and of a metallic compound 1ncluding compounds of aluminium, and in" the specification of the said Letters Patent No. 15,641/09 is given an example according to which China clay is heated with soot in the presence of nitrogen.

We have now discovered that we can advantageously produce mixtures of aluminium nitrld with other nltrids by heating alumina and carbon in the presence of ni-- trogen and an oxy compound of an element- \\l]l(:l1 is also capable of yielding a stable nitrid under the conditions of working.

According to our invention it is possible to efiect the production of the' mixtures of nitrids aforesaid at comparatively low temperatures, and the reaction can be carried out in .a comparatively short time. As examples of oxy compounds which can be added to the alumina according to our invention, we mention silica and the oxids of titanium, zirconium, molybdenum, vanadium,

beryllium, cerium, uranium, and chromium,

and even small quantities of from 5 to '10 per cent, or even less. are sufiicient to produce a favorable result. Thepresence of alkali compounds or earth alkali compounds,

iron oxid, sulfids, and the like, does not adversely affect the course of the reactlon, so

I Specification of Letters Patent.

No. 15,641/09 is described the production of compounds containing silicon and'nitrogenv i'cal compound.

Patented May 21, 1912.

' Applicationfilefl June 20, '1910. Serial No. 567,927.

- that compounds containing these substances, either in combination or otherwise, I

can be employed, thus for instance silicates, tltanates, vanadates, and other minerals can be added to the alumina, or naturally occurring mixtures of alumina with any of these compounds, such for instance as bauxite, can be employed. For instance, the naturally occurring bauxite containing silica and titanium oxid (white bauxite) can be treated with carbon and nitrogen and in this case the further addition of oxy compounds actigrade, a mixture of forty-eight parts of anhydrous alumina, twenty-four parts of pure quartz, and twenty-eight parts of coal, while passing-a current of nitrogen over the mixture. The resulting product contains aluminium nitrid and silicon nit-rid, either in'the form of a mixture or as-a chem- Example 2: Mix together sixty parts of anhydrous alumina, fifteen parts of rutile (TiO and twenty-five parts of anthra cite. Press the mixture into the form of briquets and placethem infire-proo-f chamotte saggers, and F'the'ri-"heat the mixture for twenty hours inthefpre's'ence of, nitrogen at from fourteen hundred, to fourteen hundred and fifty, degrees cen'tigrade.- The resulting product contains titanium nitrid and aluminium nitrid, eitherin the form. of

a mixture or as a .chemical compound;

Example 3: Heat together for five; hours,

at'fifteen hundred and fifty degrees-tenth grade, seventy parts of bauxite, six-parts. of chromium oxid, and twenty-four parts 'of' soot, while'pass-ing a current of nitrogen over the mixture.- The resulting product contains aluminium nitrid. together with a little chromium nit-rid and silicon nitrid.

Example': Heat together, for two hours, at sixteen hundred degrees centigrade, in a current of nitrogen, seventy-four parts of bauxite (Containing sixteen per cent. of silica, two per cent. of titanium dioxid, and traces of vanadium and chromium), and twenty-six parts of ground coke. Theresulting product contains aluminium nitrid together with some silicon ni rid and small quantities of titanium nitrid, vanadium nitrid and chromium nitrid.

In the above examples, instead of the temperatures given, higher temperatures may be employed, forinstance, the mixtures may be heated in an electric furnace.

' Now what we claim is '1. The process of producing nitrids by heating alumina and carbon in the presence of nitrogen and an oxy compound of an element which is also capable of yielding a stable nitrid under the conditions of Working while employing atemperature lying between 1400 and 2,000 C. I

2. The process of producing nitrid's' by heating alumina and carbon in the presence with carbon in the presence of nitrogen while employing a temperature'lying between 1400 and 2,000 C.

4. The process of producing nitrids by heating forty-eight parts of alumina and twenty-eight parts of carbon int-he presence of nitrogen and of twenty-four, parts .of

quartz, at a temperature of about 1500 C.

a In testimony whereof we have hereunto set our hands in the presence of two sub scribing Witnesses.

CARL BOSCH. ALWIN MITTASCH. Witnesses:

JOHN 'ALEXANDER LLOYD, ERNEST L. Ivns. 

